The disclosure relates generally to rotorcraft structural fault-detection and isolation using virtual monitoring of rotorcraft responses (e.g., loads), and more specifically, using response measurements in conjunction with virtual estimates to detect and isolate faults while adequately compensating for the normal variation in responses induced by changes in operating state. Vehicles and dynamic components thereof are subject to structural faults, including cracks, elastomeric degradation, delamination, penetration, erosion, creep, buckling, etc. Automatically detecting faults (e.g., determining whether a fault has occurred) and isolating faults (e.g., determining which fault has occurred) enhances vehicle safety and reliability and reduces maintenance costs. For example, with respect to an aircraft, because of the sheer number of possible structural fault conditions, in most cases it is impractical to install specialized sensors (e.g., crack sensors) on the aircraft dedicated to detecting and isolating every single fault condition.